In an effort to efficiently and effectively collect animal urine and/or feces, various methods and compositions are known to utilize absorbent materials in litter boxes and animal cages. In particular, clays (primarily bentonite) have been used as a base material for absorbent animal litters for some time. These materials become tacky when wetted, thereby forming a “clump” that is easily removed from a litter box. Many animals, especially felines, will often refuse to use a litter box that is not kept scrupulously clean. Clumpable animal litters facilitate the ease of cleaning, because otherwise the litter box has to be periodically dumped and refilled to maintain appropriate cleanliness.
Clays such as those based on the clay minerals kaolinite, illite, attapulgite, montmorillonite, sepiolite, diatomite, and the like, have been used extensively in animal litter compositions due to their water and moisture absorbing properties. However these materials have very little, if any, deodorizing properties.
Numerous attempts in prior art to modify liquid absorbing material (i.e. clays) within the litter to optimize its odor-inhibiting property are well known. One example is U.S. Pat. No. 2,895,873 to Sawyer et al., which teaches clay materials that are treated with sulfuric acid to form in-situ certain acidic salts. The treated clays neutralize basic odors that are originated from animal waste or decomposition.
Another example is PCT Application No. WO 0053001 to Simmler-Hübenthal et al., which teaches a litter that contains clays such as bentonite and a solid peroxo compound such as magnesium or calcium peroxide.
Another example is European Patent No. EP 1240821 to Haimerl et al., which teaches an animal litter that includes peroxo compound and calcium bentonite that is treated with hops extract to achieve a beta-acid content of 900 ppm.
In yet another example, U.S. Patent No. 2006/0088498 to Martin et al. teaches an animal litter that contains a solvent-activated reactor. The reactor is formed from a core that contains reactants such as calcium and magnesium peroxide.
Although the above-mentioned litters reduce odors to some degree, it is still desirable to further optimize liquid absorbing materials to achieve drastic reduction of malodors, and to simultaneously provide an economical method to produce such litter.